NEW YORK (AP) — Health officials said Thursday that there’s no evidence bird flu is spreading between people after investigating a mysterious infection in Missouri.

The illness reported last month was different from the 30 other bird flu infections in people in the U.S. so far this year. Those cases have been in farmworkers who had contact with infected dairy cows or chickens.

There was no known contact with an infected animal in the Missouri case, but health officials said Thursday that’s the only remaining explanation.

“There is no evidence of person-to-person transmission,” said Dr. Demetre Daskalakis of the Centers for Disease Control and Prevention.

The H5N1 bird flu has been spreading widely in the U.S. among wild birds, poultry, cows and a number of other animals. Its growing presence increases the chances that people will be exposed, and potentially catch it, officials say.

The most recent of the 31 confirmed human cases are two workers at a commercial egg farm in Franklin County, in southeast Washington state. The rest: 15 in California, 10 in Colorado, two in Michigan, one in Texas and the unusual one in Missouri. Symptoms have been mostly mild, including eye redness.

Few details have been released about the Missouri case. The person had preexisting health problems and was hospitalized in late August. The patient was given a test for flu that was positive for influenza A, a broad virus category. Further testing found partial genetic sequences similar to bird flu viruses from U.S. dairy cows.

Because the Missouri person did not work at a farm and had no known contact with an infected animal, health officials have been looking into the possibility it had come from another person with an undetected infection. That kind of spread would be a worrisome sign the virus might be turning into a more common threat to humans.

They did complicated blood testing of the patient, five hospital workers, and a person described as a “household contact” of the patient — looking for antibodies that would serve as proof of a past infection. The household contact got a stomach illness at the same time as the patient, but was not initially tested.

On Thursday, CDC officials said test results were negative for the health care workers. The patient and the household contact showed signs of past infection in one round of testing, but not in others. Neither met the World Health Organization’s blood testing threshold for a bird flu case. The household contact is not part of the U.S. tally.

Since they both got sick at the same time, officials believe the patient and the contact were exposed together to some unknown animal or animal product — ruling out spread of the virus from one of them to the other, Daskalakis said.

LOS ANGELES (AP) — Shohei Ohtani’s 50th home run ball has sold at auction for nearly $4.4 million, a record high price not just for a baseball, but for any ball in any sport, the auctioneer said Wednesday.

Ohtani became the first player in baseball history to hit 50 homers and steal 50 bases in a season, reaching the milestone on Sept. 19 when the Los Angeles Dodgers star hit his second of three homers against the Marlins.

“We received bids from around the world, a testament to the significance of this iconic collectible and Ohtani’s impact on sports, and I’m thrilled for the winning bidder,” Ken Goldin, the founder and CEO of auctioneer Goldin Auctions said in a statement.

The auction opened on Sept. 27 with a starting bid of $500,000 and closed just after midnight on Wednesday. The auctioneer said it could not disclose any information about the winning bidder.

The auction has been overshadowed by the litigation over ownership of the ball. Christian Zacek walked out of Miami’s LoanDepot Park with the ball after gaining possession in the left-field stands. Max Matus and Joseph Davidov each claim in separate lawsuits that they grabbed the ball first.

All the parties involved in the litigation agreed that the auction should continue.

Matus’ lawsuit claims that the Florida resident — who was celebrating his 18th birthday — gained possession of the Ohtani ball before Zacek took it away. Davidov claims in his suit that he was able to “firmly and completely grab the ball in his left hand while it was on the ground, successfully obtaining possession of the 50/50 ball.”

Ohtani and the Dodgers are preparing for Game 1 of the World Series scheduled for Friday night.

DENVER (AP) — E. coli food poisoning linked to McDonald’s Quarter Pounder hamburgers has sickened at least 49 people in 10 states, including one person who died and 10 who were hospitalized, federal health officials said Tuesday.

The death was reported in an older person in Colorado, and one child has been hospitalized with severe kidney complications, the U.S. Centers for Disease Control and Prevention reported.

Infections were reported between Sept. 27 and Oct. 11, in Colorado, Iowa, Kansas, Missouri, Montana, Nebraska, Oregon, Utah, Wisconsin and Wyoming. Colorado has the most cases, 26, followed by Nebraska with nine.

Everyone interviewed in connection with the outbreak had reported eating at McDonald’s before falling ill and most mentioned eating Quarter Pounder hamburgers, the CDC said. The U.S. Agriculture Department, the Food and Drug Administration and state health officials are also investigating.

A specific ingredient has not been identified as the cause, but investigators are focused on onions and beef. A preliminary FDA investigation suggests that slivered onions served on the burgers are a likely source of contamination. The USDA is investigating the hamburger patties.

In a statement, McDonald’s officials said that initial findings suggest that some illnesses are linked to onions sourced from a single supplier. The company has halted distribution of the slivered onions and temporarily removed the Quarter Pounder from menus in the affected states, and also in portions of Idaho, Nevada, New Mexico and Oklahoma.

“We take food safety extremely seriously and it’s the right thing to do,” the statement said.

E. coli bacteria are harbored in the guts of animals and found in the environment. Infections can cause severe illness, including fever, stomach cramps and bloody diarrhea. People who develop symptoms of E. coli poisoning should seek health care immediately and tell the provider what they ate.

The news comes in an already tough year for the Chicago-based McDonald’s chain. Its global same-store sales fell for the first time in nearly four years in the second quarter as inflation-weary customers skipped eating out or chose cheaper options. The company responded with a $5 meal deal, which was introduced at U.S. restaurants in late June and was recently extended through December. The deal doesn’t include the Quarter Pounder.

McDonald’s shares dropped 9% in after-hours trading Tuesday after the CDC’s announcement.

The type of bacteria implicated in this outbreak, E. coli O157:H7, causes about 74,000 infections in the U.S. each year, leading to more than 2,000 hospitalizations and 61 deaths. Infections are especially dangerous for children younger than 5 and can cause acute kidney failure.